title: Prospective comparison of cirrus and stratus optical coherence tomography for quantifying retinal thickness.
abstract: OBJECTIVE
  To compare Cirrus Fourier-domain optical coherence tomography (OCT) with Stratus time-domain OCT for imaging retinal diseases and quantifying retinal thickness (RT) of all nine OCT zones, central macular thickness, and average macular thickness in eyes with and without macular edema.
  
  
  METHODS
  Prospective comparison between two OCT systems.
  
  
  METHODS
  RT measurements were performed in 120 eyes of 60 patients suspected of having increased retina thickness using both Stratus and Cirrus OCT on the same day. Twenty-one eyes had both 512 x 128 and 200 x 200 Cirrus cube scans done.
  
  
  RESULTS
  Data from 101 eyes (53 patients) were analyzed; 46 eyes (45.5%) had macular edema on clinical examination (Group 1), whereas 55 eyes (54.4%) had no clinical evidence of macular edema (Group 2). There was modest correlation between all thickness measurements in 909 zones and each group (range of Pearson correlation, 0.51 to 0.89) and average value was significantly greater when measured with Cirrus OCT for all eyes (mean difference, 43.2 microm; P < .0001). There were few measurement differences between different resolution Cirrus cube scans.
  
  
  CONCLUSIONS
  Cirrus OCT measures RT approximately 43 microm greater than Stratus OCT, which is likely attributable to Cirrus OCT detection of the outer band of the retinal pigment epithelium vs Stratus OCT detection of the inner/outer segment photoreceptor junction. All zones showed a wide degree of variability in correlation. Both Cirrus cube scans provide similar data. Future studies comparing these systems might consider utilizing average macular thickness values, which reflect macular volume and may provide more consistent measurements.
authors.affiliation: University of Chicago Hospitals, Ophthalmology and Visual Sciences, Chicago, Illinois, USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Kiernan
authors.forename: Seenu M
authors.initials: SM
authors.lastname: Hariprasad
authors.forename: Eric K
authors.initials: EK
authors.lastname: Chin
authors.forename: Claire L
authors.initials: CL
authors.lastname: Kiernan
authors.forename: James
authors.initials: J
authors.lastname: Rago
authors.forename: William F
authors.initials: WF
authors.lastname: Mieler
mesh_terms: D003941:Diagnostic Techniques, Ophthalmological; D005583:Fourier Analysis; D006801:Humans; D008269:Macular Edema / Q000175:diagnosis* / Q000209:etiology; D011446:Prospective Studies; D012160:Retina / Q000473:pathology*; D012164:Retinal Diseases / Q000150:complications; D041623:Tomography, Optical Coherence / Q000295:instrumentation / Q000379:methods*